Tire Pressure

[TommyHarris]

I get advice all over the map about tire pressure. 2020 Fleetwood Pace Arrow 33D, recent purchase. What is your experience with this? If I reduce the pressure in the front tires by ten pounds let’s say, do I reduce the pressure in the rears the same? Looking for thoughts…

[Skip426]

Without your loaded for travel weight and the tire manufactures inflation chart ; anything you do/hear is a guess!

[theboondork.]

One of the things you could do is go to a Escapees club campground where they have a "SmartWeigh." And they will put a scale under each tire, and with the information written on your tires, and the information about your RV, they will tell you what air pressure you should have in each of your tires at your current weight. The last time I had this done in Congress Arizona at cost me about 50 bucks but it was worth it.

theboondork.com

[mr.tommy]

Having proper air pressure is not a guessing game. It's math. To calculate proper air pressure in your MH tires takes several things into consideration. Without explaining it all here, here's a YT video that shows you everything you need to know.

https://www.youtube.com/watch?v=Q_NuEoBIxe8&t=598s

[KanzKran]

Get it weighed, and use the minimum inflation pressure for that tire size and load, with some extra (like 5% or more) to allow for side-to-side unbalance, and so you're not chasing pressures every morning.


Until you get it weighed, use the manufacturer's charted pressure, wherever that may be.

[jadatis]

I can do some educated guessing if you give more data.
That is from motorhome howmany axles and if duallload behind.
Then of every axle GAWR and GVWR would be nice too.

Then of tires next.
1. Maximum load or loadindex
2. Loadrange or pressure behind AT written on sidewall
3. not that important, but speedcode
Sises would be nice too.

Then in general weigt on front stays about the same, and front seldom overloaded.
Rear needs mostly higher then front for single axle , singleload , anddualload axle lower then front.

So lowering front by 10 psi if wise, does not mean you can lower behind too.

[boomersooner]

Originally Posted by KanzKran

Get it weighed, and use the minimum inflation pressure for that tire size and load, with some extra (like 5% or more) to allow for side-to-side unbalance, and so you're not chasing pressures every morning.


Until you get it weighed, use the manufacturer's charted pressure, wherever that may be.

[MN_Traveler]

X2 tthat this is not a guessing game. Watch that video link listed above. There has got to be a truck stop near you with a Cat truck scale. Get there ASAP and get your axle weights (fully loaded for travel), then adjust your tire pressures front and rear based on those weights and your tires inflation charts. Until them, use the sidewall max pressures (this will make for rough ride / difficult handling, but at least will take you away from causing damage to the tire)

The issue of whether to add an additional 5-10 psi is a hotly debated one. I happen to add an additional 10 psi because then i dont need to get out and adjust the tire pressures on a cold morning (did that at first ... that got old REAL fast.

Do NOT arbitrarily reduce the pressures in your steers (or anywhere for that matter). Tires with too low a pressure for the weight on them cause damage to the tire, and are an invitation to a blowout.

[NXR]

Originally Posted by TommyHarris

I get advice all over the map about tire pressure. 2020 Fleetwood Pace Arrow 33D, recent purchase. What is your experience with this? If I reduce the pressure in the front tires by ten pounds let’s say, do I reduce the pressure in the rears the same? Looking for thoughts…

Somewhere inside you have a sticker that shows the tire pressure for the front tires and for the rear tires. Per DOT regulations the sticker must show the MINIMUM pressure required to safely support the design weight rating for each axle known as GAWR, Gross Axle Weight Rating.

That tire pressure is valid for the tires installed by the manufacturer. Since you have a 2020 you probably have the original tires.

Unlike car and trailer tires, motorhome tires should have their pressure set using the tire manufacturer's inflation charts AND for the actual weight.

For example, I have Michelin XRV tires sized 235/80R22.5 with a cold pressure of 110 PSI molded into the tire sidewall.

My sticker says 90 PSI for all four tires.

When I had the motorhome fully loaded for a long trip, full fuel, full fresh water, food, dogs, etc. the CAT Scale showed I was close to the GVWR rating and close to the GAWR ratings.

So I choose to run the sticker tire pressure of 90 PSI + 5 lbs or so to accommodate for colder air temperatures dropping the tire pressure.

A tire that is run with 20% less pressure than required to support the actual weight is considered flat and susceptible to internal, unseen damage.

So I set my TPMS Low Pressure alarm for 10% low or 81 PSI because I never want to let the tires drop to 72 PSI.

Hope this explains the reasons why actual weight is important.

Ray

[Bylandorsea]

The Newmar dealer told me for best ride/handling on a 4326 : 110 steers, 85 drive and 100 tag.

[mountainkowboy]

According to Toyo, the lowest I can run my 19.5's are 80 psi. According to Toyo's weight inflation charts, my coach AT FULL gvwr doesn't reach the weight rating of my tires at 80 psi.

[Crasher]

Here is everything you need to learn/know about tire pressure.

https://www.irv2.com/forums/f258/jus...ml#post3850777

[Hurricane-TX]

I will never understand the added PSI that some folks use. I always figured the tire manufacturer's testing resulted in the best performance versus longevity for each particular tire. If you add more, you are leaving their tested performance spec.

[jadatis]

Answer to post #13.
The tiremaker calculates maxload for reference- pressure and reference- speed , so if you drive that speed constantly with maxload on tire and reference-pressure in tire, you wont overheat any part of tire.

Only testing they might do, is if that dont happen.
Also lower loads at lower pressure has that goal.

So adding a reserve for inacuracies of 10% is wise.